iText is a PDF library that allows you to CREATE, ADAPT, INSPECT and MAINTAIN documents in the Portable Document Format (PDF):
- Generate documents and reports based on data from an XML file or a database
- Create maps and books, exploiting numerous interactive features available in PDF
- Add bookmarks, page numbers, watermarks, and other features to existing PDF documents
- Split or concatenate pages from existing PDF files
- Fill out interactive forms
- Serve dynamically generated or manipulated PDF documents to a web browser
iText is used by Java, .NET, Android and GAE developers to enhance their applications with PDF functionality.
iTextSharp is the .NET port.
Several iText engineers are actively supporting the project on the iText mailing-list itext-questions@lists.sourceforge.net and on StackOverflow: http://stackoverflow.com/questions/tagged/itext

SubtitleCreator allows you to create new subtitles for your DVD's. It has a Wizard interface, advanced synchronization features, DVD preview, and a simple WYSIWYG editor. The latest version even has support for Karaoke.

ZedGraph is a class library, user control, and web control for .net, written in C#, for drawing 2D Line, Bar, and Pie Charts. It features full, detailed customization capabilities, but most options have defaults for ease of use.

Dotnet IL Editor (DILE) allows disassembling and debugging .NET 1.0/1.1/2.0/3.0/3.5/4.0 applications without source code or .pdb files. It can debug even itself or the assemblies of the .NET Framework on IL level.

Fast Artificial Neural Network Library is a free open source neural network library, which implements multilayer artificial neural networks in C with support for both fully connected and sparsely connected networks. Cross-platform execution in both fixed and floating point are supported. It includes a framework for easy handling of training data sets. It is easy to use, versatile, well documented, and fast. Bindings to more than 15 programming languages are available. An easy to read introduction article and a reference manual accompanies the library with examples and recommendations on how to use the library. Several graphical user interfaces are also available for the library.

ChronosXP is a planetary hours astrology program for Windows. It runs from the system tray where it displays a glyph corresponding to the current planetary hour. Planetary hours/days can also be viewed for any given time or location.

The Regulator is an advanced Regular expressions testing tool, featuring syntax highlighting and web-service integration with Regexlib.com's database of online regular expressions.
See more info at http://regulator.sourceforge.net